Colorimetric comparison between different filtered IOLs and human crystalline lenses at various ages

Purpose To perform the colorimetric characterization of two different blue light filtered IOLs (Intra Ocular Lenses, from Alcon, USA and Hoya Corporation, Japan) and one UV-violet filtered IOL (Bausch & Lomb, USA) comparing them with standard UV filtered IOL (Alcon) and human crystalline lenses at various ages. Methods Three IOLs of each model with different dioptric power (16, 21 and 26 D) were analyzed. The colorimetric coordinates of the IOLs were calculated by measuring their transmission spectra by a spectrophotometric technique. Consequently, we defined a parameter (ΔE) proportional to the perceived color differences. A comparison was then performed between the various IOLs and human crystalline lenses of different ages (4, 22, 41, 53 and 72 years) considered from the literature. The CIE (Commission Internationale de l'Éclairage) standards were adopted for the colorimetric analysis. Results The color distance ΔE was calculated for the 4 IOL models considered, respect to human lenses at different ages between 4 and 72 years. The maximum ΔE value was found respect to the standard UV filtered IOL for any other crystalline lens age and greatest for a human 72 year old lens. The minimum value for ΔE was obtained for both blue-filtered IOLs respect to middle-aged human lenses. Conclusion None of the analyzed IOLs has the same colorimetric performance of the human crystalline lens. The two blue-filtered IOLs reproduce at best the human lens yellowing of 20 to 50 years, among all the tested IOLs.